The present invention relates to a myocardial stabilizer for immobilizing a particular part of a working heart, so as to enable an indicated operation on heart wall structures, particularly the coronary arteries.
For illustration of the invention there may be considered the most frequent cardiosurgical operation, which is indisputably a direct revascularization of the myocardium through operation on coronary arteries. Most of these operations are still performed using extra-corporeal circulation on an arrested heart. In recent years, however, a method has been used more and more often in indicated cases where reconstruction, i.e., peripheral anastomosis of vascular substitute, is feasible on a working heart without its arrest and without using extra-corporeal circulation. This means, of course, the risk in these operations is taken to another, substantially lower level in order.
Anastomosis of the vascular substitute, most often of the patient's veins themselves, is a delicate operation. When applied to as delicate an artery as the coronary artery, a necessary and sufficient condition is a perfect technical execution for the operation to be viewed as successful. The coronary artery is located under the epicardium, and its movement is therefore connected with the heart muscle movement itself. Since the frequency of cardiac beats cannot be decreased below a certain level, this method has its physiological limits. Thus, there is a certain contradiction in the necessity of a perfect placing of stitches into edges of a longitudinally opened coronary artery, on the one hand, and a continuous movement of the operation field, i.e., the heart and artery, on the other hand.
At the present time, there are two devices which are applied to immobilize the portion of the coronary artery to be operated on during the operation. In principle, these involve something like a fork with arms either joined together or individually controlled. One method brings calm to the operation field by applying pressure on a specific point of the cardiac muscle. Another method consists in contacting a respective area of the cardiac muscle with a surface of the device which is provided with suction holes, so that the muscle area is sucked into the device at the contact point of the device and the cardiac muscle.
These devices are much in use at the present time. However, they have their disadvantages. Thus, the handling of a device using pressure cannot exclude the possibility of pressure damage to the cardiac wall structures, particularly with longer operations and the application of higher pressures. Other disadvantages of these methods include limits on pressure adjustment, the tendency of a moving cardiac muscle to slip out from under the device, and the impossibility of using these devices, in practice, for all coronary arteries now being reconstructed, regardless of their anatomical position.
The device using a vacuum or suction principle is an improvement over the previous one. The stabilizer OCTOPUS.TM. is considered the most acceptable. It is characterized by two independent flexible arms with terminals of various forms provided with various numbers of suction holes. The bases of the arms and the whole suction mechanism are placed outside the operating table, and the surgeon handles only the terminals, which he can place as desired and then clamp the terminal walls on a given area by connecting the suction. This enables access even to coronary arteries on the adverse side of the heart.
A disadvantage of this procedure is again the possible damage of the cardiac muscle structures by negative pressure and generation of slight subepicardial and myocardial bleeding, the long-term consequences of which are not yet quite clear. In principle, there arises a range of small phenomena which are colloquially referred to in some places as "suckflecks."
Both of these devices are, in their various modifications, also relatively quite expensive. Therefore, there is a need in the art for a myocardial stabilizer to immobilize a particular part of a working heart to enable an operation on the coronary arteries, without the disadvantages of the above-described prior art devices and procedures.